The specific objectives of the proposed research are organized into two areas of experimental and theoretical work. In the first area, functional measurement of acoustic features in speech perception utilizes functional measurement to study acoustic features in speech perception. The approach allows the development and evaluation of quantitative models of how the acoustic features are combined to arrive at recognition of a speech sound. The goal is to contribute to the definition of the acoustic features in speech perception and to determine what combinatorial algorithms can describe how these features are integrated to arrive at recognition of speech sounds. The objective of The Role of acoustic structure and syntactic-semantc context in speech perception is to evaluate the relative contribution of the acoustic suprasegmental structure and the syntactic-sematic context in phrases and sentences with lexical, syntactic, or semantic ambiguities. The goals are to isolate the acoustic features of suprasegmental structure and to determine how these features are integrated with the information provided by syntactic and semantic context.